During fabricating a transmission type structure and a top emission assembly in a large-size inverted OLED (organic light emitting diode) display panel, it is required that light should emit from a cathode. In case the cathode is thin, there is no need to consider its work function However, in case the cathode is very thin, the cathode may suffer from problems like disconnection or its metal tends to be oxidized, so that the conductivity of the cathode is not satisfactory. Besides, since an OLED is drove by a current, in case a external wire is too long or thin, there is a large voltage gradient between the OLED and the external circuit, so that a voltage which is actually applied to the OLED decreases, and the intensity of light from an OLED panel is reduced. Meanwhile, since the resistivity of ITO from which an anode is formed is relatively large, this easily leads to external power consumption. Therefore, in the existing technology, an auxiliary electrode is provided to reduce voltage gradient, increase light path, and reduce driving voltage. In particular, the auxiliary electrode can be made from Cr, Al, Cr/Al/Cr, Mo/Al/Mo, or the like.
However, during fabricating the auxiliary electrode, it is required to add a process for sputtering metal and a process for etching, which increases the fabricating cost of OLED.